The present invention relates to ventilated enclosures and, more particularly, to a ventilated enclosure having a vortex baffle to efficiently provide ventilation to an enclosure, such as a chemical fume hood.
A chemical fume hood is a highly specialized ventilated enclosure. It is a secondary safety device intended to contain fumes and vapors that may be harmful or noxious to a user standing in front of the hood or enclosure. A volume of air is passed through the hood or enclosure to carry fumes and vapors away from the user. Operations or chemistry that produce harmful or noxious fumes are done inside a chemical fume hood. A person using the hood will reach inside the hood to manipulate the operation or chemistry being conducted. The chemical fume hood is intended to protect a person's nose and mouth area from substances at an arm's length. Chemical fume hoods have a sash that may be opened or closed. The sash is a physical barrier between the person and the interior of the hood. A chemical fume hood is used by positioning the sash and the sash may be opened, closed or anywhere in between.
Conventional fume hoods have baffles that create slots through which exhaust air flows. Traditional baffles have two exhaust slots, one in the top and one at the bottom, near the work surface. Some fume hoods have a middle slot. Air flow through these slots can become impeded by equipment and apparatus used in the fume hood.
Air flowing through an enclosure with an arbitrary interior shape is chaotic. Ventilated enclosures, such as chemical fume hoods, are safety devices intended to contain harmful airborne substances inside the enclosure. Fume hoods tend to spill due to external forces, such as the way the make-up air enters the room and movements of a person using the enclosure. Hood containment is disrupted by the way apparatus is loaded inside of the fume hood.
The only solution to poor hood performance has been to increase air flow, resulting in increased energy costs. Thus, current ventilated enclosures are inefficient because too much air is exhausted to provide too little protection to the user.
As can be seen, there is a need for an improved ventilated enclosure design that can provide user protection from fumes spilling out of the enclosure while minimizing the needed air flow to do so.